In this day of age you need options.
Thankfully most serious clients dictate the cloud service e.g. Aspera, Media Shuttle heck even Dropbox.
Personally I use frame io mostly due to the nature of my current workflow.
Really short programs no more dailies.
I was using frame io at its infancy before covid on film sets doing dailies and teasers.
Worked fine then not had the same projects of late to feel the slow down that users are experiencing.
I get the odd emails with issues but my clients are not as picky these days.
Not sure if thats a good thing 😛